T O P I C R E V I E W |
jd0331 |
Posted - 08/18/2009 : 01:27:44 AM Origin Ver. and Service Release (Select Help-->About Origin): Origin 8 Operating System: Win xp
Hi, I performed NLfit and got R square and R value. I know that they represent the goodness of fitting. What I wonder is that I do not understand the differences between R square and R value. I checked Origin tutorial, and R value is the square root of R square, which means R square is equal to the R value. However, the final R square and R value results that I got after NLfit were different. Could you explain the differences to me if you know why please?
By the way, I found that the reduced chi^2 is the chi^2 devided by Degree of freedom. What is Dof? Is it the number of data apoints? If so, why the Dof is different from that of my datapoints?
Thanks. |
1 L A T E S T R E P L I E S (Newest First) |
larry_lan |
Posted - 08/18/2009 : 02:34:29 AM Hi:
This Link can help.
R square = (R value)*(R value).
See equation (20), (22). And DOF means Degree of Freedom, which equals to (n-p) here. Where n is the number of data points and p is the number of parameters. See equation (4).
Thanks Larry OriginLab Technical Services |
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